Clinical and electrophysiological indications for surgical treatment in patients with Wolff-Parkinson-White syndrome]

20 patients with WPW syndrome and recurrent tachyarrhythmias were studied clinically and electrophysiologically. The localization and electrophysiological properties of accessory pathways and other heart structures were estimated before the surgical treatment. 13 patients (pts) suffered syncope in the course of atrial flutter or atrial fibrillation with heart rate greater than 300/min, often proceeding into ventricular fibrillation or atrioventricular tachycardia greater than 260/min, which sometimes proceeds into atrial/ventricular fibrillation. 6 pts experienced dizziness or fainted during tachyarrhythmias or rhythm changes. In 15 pts antiarrhythmic drugs in monotherapy or various combinations did not prevent recurrence of tachyarrhythmias. In 4 of 5 other pts only amiodarone was effective but the drug was discontinued due to serious adverse effects. The lack of good effect of antiarrhythmic drug therapy can be based on mutually unfavorable electrophysiologic properties of the accessory pathways and other heart structures. Pts who experienced syncope had a particularly short effective refractory period (ERP) of the accessory pathways in ante- and retro-grade direction and short ERP of the ventricle muscle. Additionally, there were multiple accessory pathways, heart muscle impairement and frequent ventricular premature beats--factors triggering the tachyarrhythmias.